Acid-functionalized PVA composite membranes for pervaporation-assisted esterification.

Composite flat-sheet membranes functionalized with imidazolium-based ionic liquids (ILs) grafted to poly(vinyl alcohol)/glutaraldehyde as a catalytic layer were developed to enhance the esterification between -butanol and acetic acid. The functionalized membranes were produced dip-coating commercial pervaporation membranes, and two distinct Brønsted-acidic ILs with an imidazolium-based cation and different (hydrogen sulfate [HSO] or bromide [Br]) anions were compared. Compact, 12 μm-thick, defect-free catalytic layers were observed on top of the pervaporation membrane supports, and the determined penetration depth of the ILs confirmed their presence in the upper part of the coating.

A versatile approach for the preparation of matrix-matched standards for LA-ICP-MS analysis - Standard addition by the spraying of liquid standards.

In the last years, LA-ICP-MS has become an attractive technique for analyzing solid samples from various research fields. However, application in material science is often hampered by the limited availability of appropriate certified reference materials, which are a precondition for accurate quantification. Thus, frequently in-house prepared standards are used, which match the sample's composition and include all elements of interest at the required concentration levels.